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Cholesterol and Triglycerides Tests

Test Overview

Cholesterol and triglyceride tests are blood tests that
measure the total amount of fatty substances (cholesterol and
triglycerides) in the blood.

Cholesterol
travels through the blood attached to a
protein. This cholesterol-protein package is called a
lipoprotein. Lipoprotein analysis (lipoprotein profile or lipid profile)
measures blood levels of
total cholesterol,
LDL cholesterol,
HDL cholesterol, and triglycerides.

Cholesterol. The body uses cholesterol to
help build cells and produce
hormones. Too much cholesterol in the blood can build
up inside arteries, forming what is known as
plaque. Large amounts of plaque increase your chances
of having a heart attack or stroke.

HDL (high-density lipoprotein) helps move cholesterol out of the body. HDL does this by binding with cholesterol in the bloodstream and
carrying it back to the liver for disposal. HDL may also reduce inflammation. A high HDL level is linked with a lower risk of heart disease.

LDL (low-density lipoprotein) carries mostly fat and only a small amount of protein from the liver to other
parts of the body. A certain level of LDL in your blood is normal and healthy because
LDL moves cholesterol to the parts of your body that
need it. But it is sometimes called "bad cholesterol" because a high level may increase your chances of developing heart disease.

VLDL: (very low-density lipoprotein)
contains very little protein. The main purpose of VLDL is to
distribute the triglyceride produced by your liver. A high VLDL cholesterol
level can cause the buildup of cholesterol in your arteries and increases your
risk of heart disease and stroke.

Triglycerides are a type of fat the body
uses to store energy and give energy to muscles. Only small amounts are found in the blood. Having a high
triglyceride level along with a high LDL cholesterol may increase your chances
of having heart disease more than having only a high LDL cholesterol
level.

Why It Is Done

To help find your risk of having heart and blood flow problems, including heart attack and stroke.

If you have unusual symptoms, such as yellow fatty deposits in
the skin (xanthomas), which may be caused by a rare genetic disease that causes
very high cholesterol levels.

Cholesterol and triglyceride screening

Talk to your doctor about when you should get a cholesterol test.

Some health organizations recommend that everyone ages 20 to 79 be checked every 4 to 6 years for the risk of heart attack and stroke, which includes a cholesterol test.footnote 1 Other organizations recommend cholesterol tests based on age and risk factors for heart disease.footnote 2

How To Prepare

Preparation may depend on the type of test you are having. You may or may not have to fast.

If your doctor tells you to fast before your test, do not eat or
drink anything except water for 9 to 12 hours before having your blood drawn.
Usually, you are allowed to take your medicines with water the morning of the
test. Fasting is not always necessary, but it may be recommended.

Do not eat high-fat foods the night before the test.

Do not drink alcohol or exercise strenuously before the
test.

Many medicines may affect the results of this
test. Be sure to tell your doctor about all the nonprescription
and prescription medicines and herbs or natural substances you take.

Tell your doctor if you have had a test such as a thyroid or
bone scan that uses a radioactive substance within the last 7 days.

Talk to your doctor about any concerns you have regarding
the need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).

How It Is Done

The health professional taking a sample
of your blood will:

Wrap an elastic band around your upper arm to stop the flow of
blood. This makes the veins below the band larger so it is easier to put a
needle into the vein.

Clean the needle site with alcohol.

Put the needle into the vein. More than one needle stick may be
needed.

Attach a tube to the needle to fill it with blood.

Remove the band from your arm when enough blood is
collected.

Put a gauze pad or cotton ball over the needle site as the needle
is removed.

Put pressure on the site and then put on a bandage.

How It Feels

The blood sample is taken from a vein in
your arm. An elastic band is wrapped around your upper arm. It may feel tight.
You may feel nothing at all from the needle, or you may feel a quick sting or
pinch.

Risks

There is very little chance of a problem from
having a blood sample taken from a vein.

You may get a small bruise at the site. You can lower the chance
of bruising by keeping pressure on the site for several minutes.

In rare cases, the vein may become swollen after the blood sample
is taken. This problem is called phlebitis. A warm compress can be used several
times a day to treat this.

Ongoing bleeding can be a problem for people with bleeding
disorders. Aspirin,
warfarin (Coumadin), and other
blood-thinning medicines can make bleeding more likely. If you have bleeding or
clotting problems, or if you take blood-thinning medicine, tell your health
professional before your blood sample is taken.

Results

Cholesterol and triglyceride tests are
blood tests that measure the total amount of fatty substances (cholesterol and
triglycerides) in the blood.

Results are
usually available within 24 hours.

What do your cholesterol numbers mean?

Your cholesterol levels can help your doctor find out your risk for having a heart attack or stroke.

But it's not just about your cholesterol. Your doctor uses your cholesterol levels plus other things to calculate your risk. These include:

Your blood pressure.

Whether or not you have diabetes.

Your age, sex, and race.

Whether or not you smoke.

You and your doctor can talk about whether you need to lower your risk and what treatment is best for you.

Pregnancy. Values are the highest during the third
trimester and usually return to the prepregnancy
levels after delivery of the baby.

What To Think About

Chylomicrons are another type of lipoprotein that are measured in a different test. Chylomicrons are in the blood
and carry fat from your intestine to your liver. They carry triglycerides to your muscles for immediate use. Or they carry triglycerides to fat tissue for storage.

Cholesterol screening is often available in supermarkets,
pharmacies, shopping malls, and other public places. Home cholesterol testing
kits also are available. The results of tests done outside a doctor's office or
lab may not be accurate. If you have cholesterol screening done outside your
doctor's office, talk with your doctor about the accuracy of the
results.

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use.
How this information was developed to help you make better health decisions.